Parser: Make skipping HTML comments optional.

src/parsing/scanner.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Features shared by parsing and pre-parsing scanners.
 
 #include "src/parsing/scanner.h"
 
 #include <stdint.h>
 
@@ skipping 18 matching lines @@
 
 
 // Default implementation for streams that do not support bookmarks.
 bool Utf16CharacterStream::SetBookmark() { return false; }
 void Utf16CharacterStream::ResetToBookmark() { UNREACHABLE(); }
 
 
 // ----------------------------------------------------------------------------
 // Scanner
 
-Scanner::Scanner(UnicodeCache* unicode_cache)
+Scanner::Scanner(UnicodeCache* unicode_cache, bool ignore_html_comments)
     : unicode_cache_(unicode_cache),
       bookmark_c0_(kNoBookmark),
       octal_pos_(Location::invalid()),
+      ignore_html_comments_(ignore_html_comments),
       found_html_comment_(false) {
   bookmark_current_.literal_chars = &bookmark_current_literal_;
   bookmark_current_.raw_literal_chars = &bookmark_current_raw_literal_;
   bookmark_next_.literal_chars = &bookmark_next_literal_;
   bookmark_next_.raw_literal_chars = &bookmark_next_raw_literal_;
 }
 
 
 void Scanner::Initialize(Utf16CharacterStream* source) {
   source_ = source;
@@ skipping 423 matching lines @@
         token = ScanString();
         break;
 
       case '<':
         // < <= << <<= <!--
         Advance();
         if (c0_ == '=') {
           token = Select(Token::LTE);
         } else if (c0_ == '<') {
           token = Select('=', Token::ASSIGN_SHL, Token::SHL);
-        } else if (c0_ == '!') {
+        } else if (c0_ == '!' && ignore_html_comments_) {

[rossberg, 2016/03/18 13:14:07]

So "skip" == "ignore" == do parse? That is confusing, IMO. Can we use one name
consistently, and one that is less ambiguous? How about "allow_html_comments"?

[vogelheim, 2016/03/18 13:56:01]

Done.

Yeah, I struggled with the naming... I like allow_* better and now use it
everywhere.

           token = ScanHtmlComment();
         } else {
           token = Token::LT;
         }
         break;
 
       case '>':
         // > >= >> >>= >>> >>>=
         Advance();
         if (c0_ == '=') {
@@ skipping 1173 matching lines @@
     backing_store_.Add(static_cast<uint8_t>((one_byte_length >> 7) | 0x80u));
   }
   backing_store_.Add(static_cast<uint8_t>(one_byte_length & 0x7f));
 
   backing_store_.AddBlock(bytes);
   return backing_store_.EndSequence().start();
 }
 
 }  // namespace internal
 }  // namespace v8